V4L/DVB (7019): V4L: add support for Syntek DC1125 webcams

This driver supports cameras with USB ID 174f:a311 or 05e1:0501,
and the ov965x sensors. These devices are found in some Asus laptops
and probably somewhere else.

It is based on the stk11xx driver written by Nicolas Vivien

Signed-off-by: Jaime Velasco Juan <jsagarribay@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

1 files changed, 578 insertions, 0 deletions

diff --git a/drivers/media/video/stk-sensor.c b/drivers/media/video/stk-sensor.c
new file mode 100644
index 000000000000..4a9a0b62efa3
--- /dev/null
+++ b/drivers/media/video/stk-sensor.c
@@ -0,0 +1,578 @@
+/* stk-sensor.c: Driver for ov96xx sensor (used in some Syntek webcams)
+ *
+ * Copyright 2007-2008 Jaime Velasco Juan <jsagarribay@gmail.com>
+ *
+ * Some parts derived from ov7670.c:
+ * Copyright 2006 One Laptop Per Child Association, Inc.  Written
+ * by Jonathan Corbet with substantial inspiration from Mark
+ * McClelland's ovcamchip code.
+ *
+ * Copyright 2006-7 Jonathan Corbet <corbet@lwn.net>
+ *
+ * This file may be distributed under the terms of the GNU General
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+/* Controlling the sensor via the STK1125 vendor specific control interface:
+ * The camera uses an OmniVision sensor and the stk1125 provides an
+ * SCCB(i2c)-USB bridge which let us program the sensor.
+ * In my case the sensor id is 0x9652, it can be read from sensor's register
+ * 0x0A and 0x0B as follows:
+ * - read register #R:
+ *   output #R to index 0x0208
+ *   output 0x0070 to index 0x0200
+ *   input 1 byte from index 0x0201 (some kind of status register)
+ *     until its value is 0x01
+ *   input 1 byte from index 0x0209. This is the value of #R
+ * - write value V to register #R
+ *   output #R to index 0x0204
+ *   output V to index 0x0205
+ *   output 0x0005 to index 0x0200
+ *   input 1 byte from index 0x0201 until its value becomes 0x04
+ */
+
+/* It seems the i2c bus is controlled with these registers */
+
+#include "stk-webcam.h"
+
+#define STK_IIC_BASE            (0x0200)
+#  define STK_IIC_OP            (STK_IIC_BASE)
+#    define STK_IIC_OP_TX       (0x05)
+#    define STK_IIC_OP_RX       (0x70)
+#  define STK_IIC_STAT          (STK_IIC_BASE+1)
+#    define STK_IIC_STAT_TX_OK  (0x04)
+#    define STK_IIC_STAT_RX_OK  (0x01)
+/* I don't know what does this register.
+ * when it is 0x00 or 0x01, we cannot talk to the sensor,
+ * other values work */
+#  define STK_IIC_ENABLE        (STK_IIC_BASE+2)
+#    define STK_IIC_ENABLE_NO   (0x00)
+/* This is what the driver writes in windows */
+#    define STK_IIC_ENABLE_YES  (0x1e)
+/*
+ * Address of the slave. Seems like the binary driver look for the
+ * sensor in multiple places, attempting a reset sequence.
+ * We only know about the ov9650
+ */
+#  define STK_IIC_ADDR          (STK_IIC_BASE+3)
+#  define STK_IIC_TX_INDEX      (STK_IIC_BASE+4)
+#  define STK_IIC_TX_VALUE      (STK_IIC_BASE+5)
+#  define STK_IIC_RX_INDEX      (STK_IIC_BASE+8)
+#  define STK_IIC_RX_VALUE      (STK_IIC_BASE+9)
+
+#define MAX_RETRIES             (50)
+
+#define SENSOR_ADDRESS          (0x60)
+
+/* From ov7670.c (These registers aren't fully accurate) */
+
+/* Registers */
+#define REG_GAIN        0x00    /* Gain lower 8 bits (rest in vref) */
+#define REG_BLUE        0x01    /* blue gain */
+#define REG_RED         0x02    /* red gain */
+#define REG_VREF        0x03    /* Pieces of GAIN, VSTART, VSTOP */
+#define REG_COM1        0x04    /* Control 1 */
+#define  COM1_CCIR656     0x40  /* CCIR656 enable */
+#define  COM1_QFMT        0x20  /* QVGA/QCIF format */
+#define  COM1_SKIP_0      0x00  /* Do not skip any row */
+#define  COM1_SKIP_2      0x04  /* Skip 2 rows of 4 */
+#define  COM1_SKIP_3      0x08  /* Skip 3 rows of 4 */
+#define REG_BAVE        0x05    /* U/B Average level */
+#define REG_GbAVE       0x06    /* Y/Gb Average level */
+#define REG_AECHH       0x07    /* AEC MS 5 bits */
+#define REG_RAVE        0x08    /* V/R Average level */
+#define REG_COM2        0x09    /* Control 2 */
+#define  COM2_SSLEEP      0x10  /* Soft sleep mode */
+#define REG_PID         0x0a    /* Product ID MSB */
+#define REG_VER         0x0b    /* Product ID LSB */
+#define REG_COM3        0x0c    /* Control 3 */
+#define  COM3_SWAP        0x40    /* Byte swap */
+#define  COM3_SCALEEN     0x08    /* Enable scaling */
+#define  COM3_DCWEN       0x04    /* Enable downsamp/crop/window */
+#define REG_COM4        0x0d    /* Control 4 */
+#define REG_COM5        0x0e    /* All "reserved" */
+#define REG_COM6        0x0f    /* Control 6 */
+#define REG_AECH        0x10    /* More bits of AEC value */
+#define REG_CLKRC       0x11    /* Clock control */
+#define   CLK_PLL         0x80    /* Enable internal PLL */
+#define   CLK_EXT         0x40    /* Use external clock directly */
+#define   CLK_SCALE       0x3f    /* Mask for internal clock scale */
+#define REG_COM7        0x12    /* Control 7 */
+#define   COM7_RESET      0x80    /* Register reset */
+#define   COM7_FMT_MASK   0x38
+#define   COM7_FMT_SXGA   0x00
+#define   COM7_FMT_VGA    0x40
+#define   COM7_FMT_CIF    0x20    /* CIF format */
+#define   COM7_FMT_QVGA   0x10    /* QVGA format */
+#define   COM7_FMT_QCIF   0x08    /* QCIF format */
+#define   COM7_RGB        0x04    /* bits 0 and 2 - RGB format */
+#define   COM7_YUV        0x00    /* YUV */
+#define   COM7_BAYER      0x01    /* Bayer format */
+#define   COM7_PBAYER     0x05    /* "Processed bayer" */
+#define REG_COM8        0x13    /* Control 8 */
+#define   COM8_FASTAEC    0x80    /* Enable fast AGC/AEC */
+#define   COM8_AECSTEP    0x40    /* Unlimited AEC step size */
+#define   COM8_BFILT      0x20    /* Band filter enable */
+#define   COM8_AGC        0x04    /* Auto gain enable */
+#define   COM8_AWB        0x02    /* White balance enable */
+#define   COM8_AEC        0x01    /* Auto exposure enable */
+#define REG_COM9        0x14    /* Control 9  - gain ceiling */
+#define REG_COM10       0x15    /* Control 10 */
+#define   COM10_HSYNC     0x40    /* HSYNC instead of HREF */
+#define   COM10_PCLK_HB   0x20    /* Suppress PCLK on horiz blank */
+#define   COM10_HREF_REV  0x08    /* Reverse HREF */
+#define   COM10_VS_LEAD   0x04    /* VSYNC on clock leading edge */
+#define   COM10_VS_NEG    0x02    /* VSYNC negative */
+#define   COM10_HS_NEG    0x01    /* HSYNC negative */
+#define REG_HSTART      0x17    /* Horiz start high bits */
+#define REG_HSTOP       0x18    /* Horiz stop high bits */
+#define REG_VSTART      0x19    /* Vert start high bits */
+#define REG_VSTOP       0x1a    /* Vert stop high bits */
+#define REG_PSHFT       0x1b    /* Pixel delay after HREF */
+#define REG_MIDH        0x1c    /* Manuf. ID high */
+#define REG_MIDL        0x1d    /* Manuf. ID low */
+#define REG_MVFP        0x1e    /* Mirror / vflip */
+#define   MVFP_MIRROR     0x20    /* Mirror image */
+#define   MVFP_FLIP       0x10    /* Vertical flip */
+
+#define REG_AEW         0x24    /* AGC upper limit */
+#define REG_AEB         0x25    /* AGC lower limit */
+#define REG_VPT         0x26    /* AGC/AEC fast mode op region */
+#define REG_ADVFL       0x2d    /* Insert dummy lines (LSB) */
+#define REG_ADVFH       0x2e    /* Insert dummy lines (MSB) */
+#define REG_HSYST       0x30    /* HSYNC rising edge delay */
+#define REG_HSYEN       0x31    /* HSYNC falling edge delay */
+#define REG_HREF        0x32    /* HREF pieces */
+#define REG_TSLB        0x3a    /* lots of stuff */
+#define   TSLB_YLAST      0x04    /* UYVY or VYUY - see com13 */
+#define   TSLB_BYTEORD    0x08    /* swap bytes in 16bit mode? */
+#define REG_COM11       0x3b    /* Control 11 */
+#define   COM11_NIGHT     0x80    /* NIght mode enable */
+#define   COM11_NMFR      0x60    /* Two bit NM frame rate */
+#define   COM11_HZAUTO    0x10    /* Auto detect 50/60 Hz */
+#define   COM11_50HZ      0x08    /* Manual 50Hz select */
+#define   COM11_EXP       0x02
+#define REG_COM12       0x3c    /* Control 12 */
+#define   COM12_HREF      0x80    /* HREF always */
+#define REG_COM13       0x3d    /* Control 13 */
+#define   COM13_GAMMA     0x80    /* Gamma enable */
+#define   COM13_UVSAT     0x40    /* UV saturation auto adjustment */
+#define   COM13_CMATRIX   0x10    /* Enable color matrix for RGB or YUV */
+#define   COM13_UVSWAP    0x01    /* V before U - w/TSLB */
+#define REG_COM14       0x3e    /* Control 14 */
+#define   COM14_DCWEN     0x10    /* DCW/PCLK-scale enable */
+#define REG_EDGE        0x3f    /* Edge enhancement factor */
+#define REG_COM15       0x40    /* Control 15 */
+#define   COM15_R10F0     0x00    /* Data range 10 to F0 */
+#define   COM15_R01FE     0x80    /*            01 to FE */
+#define   COM15_R00FF     0xc0    /*            00 to FF */
+#define   COM15_RGB565    0x10    /* RGB565 output */
+#define   COM15_RGBFIXME          0x20    /* FIXME  */
+#define   COM15_RGB555    0x30    /* RGB555 output */
+#define REG_COM16       0x41    /* Control 16 */
+#define   COM16_AWBGAIN   0x08    /* AWB gain enable */
+#define REG_COM17       0x42    /* Control 17 */
+#define   COM17_AECWIN    0xc0    /* AEC window - must match COM4 */
+#define   COM17_CBAR      0x08    /* DSP Color bar */
+
+/*
+ * This matrix defines how the colors are generated, must be
+ * tweaked to adjust hue and saturation.
+ *
+ * Order: v-red, v-green, v-blue, u-red, u-green, u-blue
+ *
+ * They are nine-bit signed quantities, with the sign bit
+ * stored in 0x58.  Sign for v-red is bit 0, and up from there.
+ */
+#define REG_CMATRIX_BASE 0x4f
+#define   CMATRIX_LEN 6
+#define REG_CMATRIX_SIGN 0x58
+
+
+#define REG_BRIGHT      0x55    /* Brightness */
+#define REG_CONTRAS     0x56    /* Contrast control */
+
+#define REG_GFIX        0x69    /* Fix gain control */
+
+#define REG_RGB444      0x8c    /* RGB 444 control */
+#define   R444_ENABLE     0x02    /* Turn on RGB444, overrides 5x5 */
+#define   R444_RGBX       0x01    /* Empty nibble at end */
+
+#define REG_HAECC1      0x9f    /* Hist AEC/AGC control 1 */
+#define REG_HAECC2      0xa0    /* Hist AEC/AGC control 2 */
+
+#define REG_BD50MAX     0xa5    /* 50hz banding step limit */
+#define REG_HAECC3      0xa6    /* Hist AEC/AGC control 3 */
+#define REG_HAECC4      0xa7    /* Hist AEC/AGC control 4 */
+#define REG_HAECC5      0xa8    /* Hist AEC/AGC control 5 */
+#define REG_HAECC6      0xa9    /* Hist AEC/AGC control 6 */
+#define REG_HAECC7      0xaa    /* Hist AEC/AGC control 7 */
+#define REG_BD60MAX     0xab    /* 60hz banding step limit */
+
+
+
+
+/* Returns 0 if OK */
+int stk_sensor_outb(struct stk_camera *dev, u8 reg, u8 val)
+{
+        int i = 0;
+        int tmpval = 0;
+
+        if (stk_camera_write_reg(dev, STK_IIC_TX_INDEX, reg))
+                return 1;
+        if (stk_camera_write_reg(dev, STK_IIC_TX_VALUE, val))
+                return 1;
+        if (stk_camera_write_reg(dev, STK_IIC_OP, STK_IIC_OP_TX))
+                return 1;
+        do {
+                if (stk_camera_read_reg(dev, STK_IIC_STAT, &tmpval))
+                        return 1;
+                i++;
+        } while (tmpval == 0 && i < MAX_RETRIES);
+        if (tmpval != STK_IIC_STAT_TX_OK) {
+                if (tmpval)
+                        STK_ERROR("stk_sensor_outb failed, status=0x%02x\n",
+                                tmpval);
+                return 1;
+        } else
+                return 0;
+}
+
+int stk_sensor_inb(struct stk_camera *dev, u8 reg, u8 *val)
+{
+        int i = 0;
+        int tmpval = 0;
+
+        if (stk_camera_write_reg(dev, STK_IIC_RX_INDEX, reg))
+                return 1;
+        if (stk_camera_write_reg(dev, STK_IIC_OP, STK_IIC_OP_RX))
+                return 1;
+        do {
+                if (stk_camera_read_reg(dev, STK_IIC_STAT, &tmpval))
+                        return 1;
+                i++;
+        } while (tmpval == 0 && i < MAX_RETRIES);
+        if (tmpval != STK_IIC_STAT_RX_OK) {
+                if (tmpval)
+                        STK_ERROR("stk_sensor_inb failed, status=0x%02x\n",
+                                tmpval);
+                return 1;
+        }
+
+        if (stk_camera_read_reg(dev, STK_IIC_RX_VALUE, &tmpval))
+                return 1;
+
+        *val = (u8) tmpval;
+        return 0;
+}
+
+static int stk_sensor_write_regvals(struct stk_camera *dev,
+                struct regval *rv)
+{
+        int ret;
+        if (rv == NULL)
+                return 0;
+        while (rv->reg != 0xff || rv->val != 0xff) {
+                ret = stk_sensor_outb(dev, rv->reg, rv->val);
+                if (ret != 0)
+                        return ret;
+                rv++;
+        }
+        return 0;
+}
+
+int stk_sensor_sleep(struct stk_camera *dev)
+{
+        u8 tmp;
+        return stk_sensor_inb(dev, REG_COM2, &tmp)
+                || stk_sensor_outb(dev, REG_COM2, tmp|COM2_SSLEEP);
+}
+
+int stk_sensor_wakeup(struct stk_camera *dev)
+{
+        u8 tmp;
+        return stk_sensor_inb(dev, REG_COM2, &tmp)
+                || stk_sensor_outb(dev, REG_COM2, tmp&~COM2_SSLEEP);
+}
+
+static struct regval ov_initvals[] = {
+        {REG_CLKRC, CLK_PLL},
+        {REG_COM11, 0x01},
+        {0x6a, 0x7d},
+        {REG_AECH, 0x40},
+        {REG_GAIN, 0x00},
+        {REG_BLUE, 0x80},
+        {REG_RED, 0x80},
+        /* Do not enable fast AEC for now */
+        /*{REG_COM8, COM8_FASTAEC|COM8_AECSTEP|COM8_BFILT|COM8_AGC|COM8_AEC},*/
+        {REG_COM8, COM8_AECSTEP|COM8_BFILT|COM8_AGC|COM8_AEC},
+        {0x39, 0x50}, {0x38, 0x93},
+        {0x37, 0x00}, {0x35, 0x81},
+        {REG_COM5, 0x20},
+        {REG_COM1, 0x00},
+        {REG_COM3, 0x00},
+        {REG_COM4, 0x00},
+        {REG_PSHFT, 0x00},
+        {0x16, 0x07},
+        {0x33, 0xe2}, {0x34, 0xbf},
+        {REG_COM16, 0x00},
+        {0x96, 0x04},
+        /* Gamma curve values */
+/*      { 0x7a, 0x20 },         { 0x7b, 0x10 },
+        { 0x7c, 0x1e },         { 0x7d, 0x35 },
+        { 0x7e, 0x5a },         { 0x7f, 0x69 },
+        { 0x80, 0x76 },         { 0x81, 0x80 },
+        { 0x82, 0x88 },         { 0x83, 0x8f },
+        { 0x84, 0x96 },         { 0x85, 0xa3 },
+        { 0x86, 0xaf },         { 0x87, 0xc4 },
+        { 0x88, 0xd7 },         { 0x89, 0xe8 },
+*/
+        {REG_GFIX, 0x40},
+        {0x8e, 0x00},
+        {REG_COM12, 0x73},
+        {0x8f, 0xdf}, {0x8b, 0x06},
+        {0x8c, 0x20},
+        {0x94, 0x88}, {0x95, 0x88},
+/*      {REG_COM15, 0xc1}, TODO */
+        {0x29, 0x3f},
+        {REG_COM6, 0x42},
+        {REG_BD50MAX, 0x80},
+        {REG_HAECC6, 0xb8}, {REG_HAECC7, 0x92},
+        {REG_BD60MAX, 0x0a},
+        {0x90, 0x00}, {0x91, 0x00},
+        {REG_HAECC1, 0x00}, {REG_HAECC2, 0x00},
+        {REG_AEW, 0x68}, {REG_AEB, 0x5c},
+        {REG_VPT, 0xc3},
+        {REG_COM9, 0x2e},
+        {0x2a, 0x00}, {0x2b, 0x00},
+
+        {0xff, 0xff}, /* END MARKER */
+};
+
+/* Probe the I2C bus and initialise the sensor chip */
+int stk_sensor_init(struct stk_camera *dev)
+{
+        u8 idl = 0;
+        u8 idh = 0;
+
+        if (stk_camera_write_reg(dev, STK_IIC_ENABLE, STK_IIC_ENABLE_YES)
+                || stk_camera_write_reg(dev, STK_IIC_ADDR, SENSOR_ADDRESS)
+                || stk_sensor_outb(dev, REG_COM7, COM7_RESET)) {
+                STK_ERROR("Sensor resetting failed\n");
+                return -ENODEV;
+        }
+        msleep(10);
+        /* Read the manufacturer ID: ov = 0x7FA2 */
+        if (stk_sensor_inb(dev, REG_MIDH, &idh)
+            || stk_sensor_inb(dev, REG_MIDL, &idl)) {
+                STK_ERROR("Strange error reading sensor ID\n");
+                return -ENODEV;
+        }
+        if (idh != 0x7F || idl != 0xA2) {
+                STK_ERROR("Huh? you don't have a sensor from ovt\n");
+                return -ENODEV;
+        }
+        if (stk_sensor_inb(dev, REG_PID, &idh)
+            || stk_sensor_inb(dev, REG_VER, &idl)) {
+                STK_ERROR("Could not read sensor model\n");
+                return -ENODEV;
+        }
+        stk_sensor_write_regvals(dev, ov_initvals);
+        msleep(10);
+        STK_INFO("OmniVision sensor detected, id %02X%02X"
+                " at address %x\n", idh, idl, SENSOR_ADDRESS);
+        return 0;
+}
+
+/* V4L2_PIX_FMT_UYVY */
+static struct regval ov_fmt_uyvy[] = {
+        {REG_TSLB, TSLB_YLAST|0x08 },
+        { 0x4f, 0x80 },         /* "matrix coefficient 1" */
+        { 0x50, 0x80 },         /* "matrix coefficient 2" */
+        { 0x51, 0    },         /* vb */
+        { 0x52, 0x22 },         /* "matrix coefficient 4" */
+        { 0x53, 0x5e },         /* "matrix coefficient 5" */
+        { 0x54, 0x80 },         /* "matrix coefficient 6" */
+        {REG_COM13, COM13_UVSAT|COM13_CMATRIX},
+        {REG_COM15, COM15_R00FF },
+        {0xff, 0xff}, /* END MARKER */
+};
+
+/* V4L2_PIX_FMT_RGB565X rrrrrggg gggbbbbb */
+static struct regval ov_fmt_rgbr[] = {
+        { REG_RGB444, 0 },      /* No RGB444 please */
+        {REG_TSLB, 0x00},
+        { REG_COM1, 0x0 },
+        { REG_COM9, 0x38 },     /* 16x gain ceiling; 0x8 is reserved bit */
+        { 0x4f, 0xb3 },         /* "matrix coefficient 1" */
+        { 0x50, 0xb3 },         /* "matrix coefficient 2" */
+        { 0x51, 0    },         /* vb */
+        { 0x52, 0x3d },         /* "matrix coefficient 4" */
+        { 0x53, 0xa7 },         /* "matrix coefficient 5" */
+        { 0x54, 0xe4 },         /* "matrix coefficient 6" */
+        { REG_COM13, COM13_GAMMA },
+        { REG_COM15, COM15_RGB565|COM15_R00FF },
+        { 0xff, 0xff },
+};
+
+/* V4L2_PIX_FMT_RGB565 gggbbbbb rrrrrggg */
+static struct regval ov_fmt_rgbp[] = {
+        { REG_RGB444, 0 },      /* No RGB444 please */
+        {REG_TSLB, TSLB_BYTEORD },
+        { REG_COM1, 0x0 },
+        { REG_COM9, 0x38 },     /* 16x gain ceiling; 0x8 is reserved bit */
+        { 0x4f, 0xb3 },         /* "matrix coefficient 1" */
+        { 0x50, 0xb3 },         /* "matrix coefficient 2" */
+        { 0x51, 0    },         /* vb */
+        { 0x52, 0x3d },         /* "matrix coefficient 4" */
+        { 0x53, 0xa7 },         /* "matrix coefficient 5" */
+        { 0x54, 0xe4 },         /* "matrix coefficient 6" */
+        { REG_COM13, COM13_GAMMA },
+        { REG_COM15, COM15_RGB565|COM15_R00FF },
+        { 0xff, 0xff },
+};
+
+/* V4L2_PIX_FMT_SRGGB8 */
+static struct regval ov_fmt_bayer[] = {
+        /* This changes color order */
+        {REG_TSLB, 0x40}, /* BGGR */
+        /* {REG_TSLB, 0x08}, */ /* BGGR with vertical image flipping */
+        {REG_COM15, COM15_R00FF },
+        {0xff, 0xff}, /* END MARKER */
+};
+/*
+ * Store a set of start/stop values into the camera.
+ */
+static int stk_sensor_set_hw(struct stk_camera *dev,
+                int hstart, int hstop, int vstart, int vstop)
+{
+        int ret;
+        unsigned char v;
+/*
+ * Horizontal: 11 bits, top 8 live in hstart and hstop.  Bottom 3 of
+ * hstart are in href[2:0], bottom 3 of hstop in href[5:3].  There is
+ * a mystery "edge offset" value in the top two bits of href.
+ */
+        ret =  stk_sensor_outb(dev, REG_HSTART, (hstart >> 3) & 0xff);
+        ret += stk_sensor_outb(dev, REG_HSTOP, (hstop >> 3) & 0xff);
+        ret += stk_sensor_inb(dev, REG_HREF, &v);
+        v = (v & 0xc0) | ((hstop & 0x7) << 3) | (hstart & 0x7);
+        msleep(10);
+        ret += stk_sensor_outb(dev, REG_HREF, v);
+/*
+ * Vertical: similar arrangement (note: this is different from ov7670.c)
+ */
+        ret += stk_sensor_outb(dev, REG_VSTART, (vstart >> 3) & 0xff);
+        ret += stk_sensor_outb(dev, REG_VSTOP, (vstop >> 3) & 0xff);
+        ret += stk_sensor_inb(dev, REG_VREF, &v);
+        v = (v & 0xc0) | ((vstop & 0x7) << 3) | (vstart & 0x7);
+        msleep(10);
+        ret += stk_sensor_outb(dev, REG_VREF, v);
+        return ret;
+}
+
+
+int stk_sensor_configure(struct stk_camera *dev)
+{
+        int com7;
+        /*
+         * We setup the sensor to output dummy lines in low-res modes,
+         * so we don't get absurdly hight framerates.
+         */
+        unsigned dummylines;
+        int flip;
+        struct regval *rv;
+
+        switch (dev->vsettings.mode) {
+        case MODE_QCIF: com7 = COM7_FMT_QCIF;
+                dummylines = 604;
+                break;
+        case MODE_QVGA: com7 = COM7_FMT_QVGA;
+                dummylines = 267;
+                break;
+        case MODE_CIF: com7 = COM7_FMT_CIF;
+                dummylines = 412;
+                break;
+        case MODE_VGA: com7 = COM7_FMT_VGA;
+                dummylines = 11;
+                break;
+        case MODE_SXGA: com7 = COM7_FMT_SXGA;
+                dummylines = 0;
+                break;
+        default: STK_ERROR("Unsupported mode %d\n", dev->vsettings.mode);
+                return -EFAULT;
+        }
+        switch (dev->vsettings.palette) {
+        case V4L2_PIX_FMT_UYVY:
+                com7 |= COM7_YUV;
+                rv = ov_fmt_uyvy;
+                break;
+        case V4L2_PIX_FMT_RGB565:
+                com7 |= COM7_RGB;
+                rv = ov_fmt_rgbp;
+                break;
+        case V4L2_PIX_FMT_RGB565X:
+                com7 |= COM7_RGB;
+                rv = ov_fmt_rgbr;
+                break;
+        case V4L2_PIX_FMT_SBGGR8:
+                com7 |= COM7_PBAYER;
+                rv = ov_fmt_bayer;
+                break;
+        default: STK_ERROR("Unsupported colorspace\n");
+                return -EFAULT;
+        }
+        /*FIXME sometimes the sensor go to a bad state
+        stk_sensor_write_regvals(dev, ov_initvals); */
+        stk_sensor_outb(dev, REG_COM7, com7);
+        msleep(50);
+        stk_sensor_write_regvals(dev, rv);
+        flip = (dev->vsettings.vflip?MVFP_FLIP:0)
+                | (dev->vsettings.hflip?MVFP_MIRROR:0);
+        stk_sensor_outb(dev, REG_MVFP, flip);
+        if (dev->vsettings.palette == V4L2_PIX_FMT_SBGGR8
+                        && !dev->vsettings.vflip)
+                stk_sensor_outb(dev, REG_TSLB, 0x08);
+        stk_sensor_outb(dev, REG_ADVFH, dummylines >> 8);
+        stk_sensor_outb(dev, REG_ADVFL, dummylines & 0xff);
+        msleep(50);
+        switch (dev->vsettings.mode) {
+        case MODE_VGA:
+                if (stk_sensor_set_hw(dev, 302, 1582, 6, 486))
+                        STK_ERROR("stk_sensor_set_hw failed (VGA)\n");
+                break;
+        case MODE_SXGA:
+        case MODE_CIF:
+        case MODE_QVGA:
+        case MODE_QCIF:
+                /*FIXME These settings seem ignored by the sensor
+                if (stk_sensor_set_hw(dev, 220, 1500, 10, 1034))
+                        STK_ERROR("stk_sensor_set_hw failed (SXGA)\n");
+                */
+                break;
+        }
+        msleep(10);
+        return 0;
+}
+
+int stk_sensor_set_brightness(struct stk_camera *dev, int br)
+{
+        if (br < 0 || br > 0xff)
+                return -EINVAL;
+        stk_sensor_outb(dev, REG_AEB, max(0x00, br - 6));
+        stk_sensor_outb(dev, REG_AEW, min(0xff, br + 6));
+        return 0;
+}
+